abstract name of clipping ops, to transtion to a more restricted set

include/utils/SkLuaCanvas.h

Index: include/utils/SkLuaCanvas.h
diff --git a/include/utils/SkLuaCanvas.h b/include/utils/SkLuaCanvas.h
index a823a47aa8c61bffe2ba64ef6ff8f96fd6c4f71d..ac29f6f272145a13c9d46915dd7ca3a752fa94ea 100644
--- a/include/utils/SkLuaCanvas.h
+++ b/include/utils/SkLuaCanvas.h
@@ -63,10 +63,10 @@ protected:
                         const uint16_t indices[], int indexCount,
                         const SkPaint&) override;
 
-    void onClipRect(const SkRect&, SkRegion::Op, ClipEdgeStyle) override;
-    void onClipRRect(const SkRRect&, SkRegion::Op, ClipEdgeStyle) override;
-    void onClipPath(const SkPath&, SkRegion::Op, ClipEdgeStyle) override;
-    void onClipRegion(const SkRegion&, SkRegion::Op) override;
+    void onClipRect(const SkRect&, ClipOp, ClipEdgeStyle) override;
+    void onClipRRect(const SkRRect&, ClipOp, ClipEdgeStyle) override;
+    void onClipPath(const SkPath&, ClipOp, ClipEdgeStyle) override;
+    void onClipRegion(const SkRegion&, ClipOp) override;
 
     void onDrawPicture(const SkPicture*, const SkMatrix*, const SkPaint*) override;